The $40 million covers the right to publish Crichton in the United States, Britain and other English-speaking markets. The sale of publication rights in other countries will lift Crichton's per-book riches well above $20 million, keeping him in the stratosphere with John Grisham and Tom Clancy.

''This change is particularly meaningful because it gives me the opportunity once again to work with (HarperCollins president) Jane Friedman, a friend and colleague,'' Crichton said in a statement.

The two started working together in 1969, on ''The Andromeda Strain,'' the first of 15 Crichton books published by Knopf.

''I feel great -- it's a nice reunion,'' Friedman said.

Friedman, who was executive vice president of Knopf, left in 1997 to head HarperCollins.

The wisdom of HarperCollins' deal will not be known for several years, as Crichton generates new sales, starting with a novel next year. Meantime, his valuable catalogue of previous titles will continue to be published by Random House, whose Ballantine imprint has re-issued Crichton's books in paperback.

Crichton's last two novels, ''Airframe'' and ''Timeline,'' sold less impressively than some of his earlier books. That may have prompted Mehta to offer less than HarperCollins to hang on to Crichton.

''We made a very aggressive offer, and it is with great regret that we were unable to come to terms with Michael Crichton on his new contract,'' Knopf senior vice president William Loverd said last night. ''We're very proud of the way we have developed Michael into one of the world's leading brand-name authors.''